Drying apparatus

ABSTRACT

An apparatus for and method of drying articles such as tubular containers each having a bottom wall, an adjoining sidewall, and an open end wherein said containers are supported in an inverted position and a drying gas moved therepast in such a manner that it circulates around and within the containers and provides efficient drying of both the interiors and exteriors thereof.

United States Patent [72] lnventor Harry W. Lee, Jr.

Richmond, Va.

[21] AppL No. 818,215

[22] Filed Apr. 22, 1969 [45] Patented Apr. 13, 1971 [73] AssigneeReynolds Metals Company Richmond, Va.

[54] DRYING APPARATUS 17 Claims, 6 Drawing Figs.

34/105 Int. Cl..... F26b 25/00 Field of Search 34/21, 103, 105

[56] References Cited UNITED STATES PATENTS 3,363,327 l/l968 Harrison eta]. 34/105 Primary Examiner-Charles Sukalo Altomey-Glenn, Palmer, Lyne,Gibbs and Thompson ABSTRACT: An apparatus for and method of dryingarticles such as tubular containers each having a bottom wall, anadjoining sidewall, and an open end wherein said containers aresupported in an inverted position and a drying gas moved therepast insuch a manner that it circulates around and within the containers andprovides efficient drying of both the interiors and exteriors thereof.

Patented April 13, 1971 3,574,952

2 Sheets-Sheet 1 I PI T 7I SJ 1| 1| n 1. 68 36/ I I 21- sol HARRY x l lifJR.

I v BY *cmmw, -L 4 68 1 H g qibb g 4- I 1 w7p9w 8 HIS ATTORNEYSPatented, A ril 13, 1911 3,514,952

2 Sheets-Sheet 2 l 57 x I I 72 4 I l I FIG-6 3O {3O 34 74 V 35 L74 T 64i INVENTOR 63 2 HARRY w. LEE, JR.

P 'MQJ Lan UVLd IHAOMPW HIS ATTORNEYS DRYING APPARATUS BACKGROUND OF THEINVENTION Many apparatus and methods have been proposed heretofore fordrying tubular containers, such as cans each having one open end, forexample, by passing a drying gas thereover. However, such previouslyproposed apparatus and methods do not provide efficient drying of theinteriors of such cans because of their inability to circulate thedrying gas inside each can.

SUMMARY exemplary embodiment thereof presented in the accompanyingdrawings proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings show apresent exemplary embodiment of this invention, in which:

FIG. 1 is a perspective view with parts broken away illustrating oneexemplary embodiment of the apparatus of this invention used to drytubular containers each having only one open end; v

FIG. 2 is a view taken essentially on the line 2-2 of FIG. 1;

FIG. 3 is a greatly enlarged fragmentary perspective view of a portionof the conveyor comprising the apparatus of FIG. 1;

FIG. 4 is a side elevation with parts broken away of the apparatus ofFIG. I particularly highlighting the method utilized to circulate adrying gas over the containers;

FIG. 5 is a greatly enlarged fragmentary view taken essentially on theline 5-5 of FIG. 4; and

FIG. 6 is a greatly enlarged fragmentary view with an exaggeratedspacing between containers particularly illustrating the manner in whicha drying gas is circulated past a plurality of inverted containers toprovide rapid and efficient drying of both the interiors and exteriorsthereof while providing circulation of gas within each invertedcontainer.

DESCRIPTION OF ILLUSTRATED EMBODIMENT Reference is now made to FIGS. l-3of the drawings which illustrate one exemplary embodiment of theapparatus and method of this invention which is designated generally bythe reference numeral 20. The apparatus comprises an endless chainconveyor 21 which has a maximum open area which allows substantiallyunobstructed flow therethrough of a drying gas in a directionperpendicular to its supporting surface. The conveyor 21 has ahorizontally extending portion 22 which is adapted to support aplurality of elongated tubular articles shown as a plurality of tubularcontainers or cans 23 each having a bottom wall 24 and an adjoiningsidewall 25 terminating in an end edge 26 defining an open end, see FIG.6.

The cans 23 are supported on the horizontally extending portion 22 ofthe conveyor 21 with their axes arranged vertically and in parallelrelation. A system is provided for circulating a drying gas or fluid,heated air in this example of the invention, around the cans 23 so as toprovide efficient simultaneous drying of both the interiors andexteriors of such cans.

The apparatus 20 has means for directing the drying air, indicated inthe drawings by a plurality of arrows 30, so that the air is directedtoward the cans 23 at high velocity and in a plurality of closely spacedjets, with the spacing between such jets assuring that at least one jetis directed normally toward each of the cans 23 and in particularsubstantially toward the central portion of the bottom wall 24 of eachcan 23. The apparatus 20 has means for dampening any turbulence in theheated air as it approaches the cans 23 and in this example of theinvention the dampening means comprises a plurality of sets 31 of screenand plate assemblies arranged parallel to the horizontal portion 22 ofthe conveyor 21 and with each set being defined by a perforated plate 32adjoined by a screen 33 arranged upstream thereof. The apparatus 20 alsohas a planar sheet 34 which has a plurality of spaced openings 35provided therein and the openings 35 define the previously mentionedjets which assure that heated air is directed toward the cans 23 at highvelocity.

The apparatus 20 also has a flow control device arranged beneath thehorizontal portion 22 of conveyor 21 which is used to create a negativepressure beneath the conveyor and cans 23 and in this example of theinvention such flow control device comprisesa plate 36 having aplurality of apertures 37 therein. The plate 36 with its apertures 37operates to restrict airflow in a controlled manner creating a venturieffect which causes heated air to circulate inside the inverted cans 23and provide an efficient drying of the can interiors. It will also beappreciated that the construction of the conveyor 21 may be such that itcooperates with the plate 36 to provide controlled flow producing theabove-mentioned venturi effect.

The apparatus 20 has what will be referred to as a drying chamber 40defined by a housing 41 which has openings 42 and 43 at opposite endsthereof which allow the conveyor 21 with the cans 23 supported thereonin an inverted manner to pass through the chamber 40 in a continuousmanner to enable high-speed drying thereof. The housing portion 41 andhence drying chamber 40 is supported on an associated supporting floorby a plurality of spaced vertical legs 44.

The apparatus 20 also includes a duct assembly 45 arranged beneath thehousing portion 41 and the assembly 45 has an upstream end fastened insealed relation to the housing portion 41 and a downstream end fastenedin sealed relation to the inlet of a centrifugal fan 46. The apparatus20 also has a duct assembly 48 which includes a verticallyextendingportion 50 which is fastened in sealed relation to thedischarge of the fan 46, a vertical downwardly flaring frustopyramidalsection 51 fastened in sealed relation to the top portion of the housing41 and a substantially U-shaped transition section 52 connecting thevertical sections 50 and 51.

The fan 46 has a shaft 53 extending therefrom which is supported by apair of antifriction bearings 54 carried on a support 55 and the shaft53 is driven by a suitable drive motor 56. The apparatus 20 has aplurality of heaters 57 which may be in the form of electrical heaterswhich are provided with electrical power from any suitable power sourceand are utilized to heat the air which is used to dry the cans 23.

As will be apparent particularly from FIG. 4 of the drawings, the aircirculating system for the apparatus 20 comprises a closed loop systemwhich circulates heated air past the containers 23 in the drying chamber40. The air is then recirculated past the heaters 57 to remove anymoisture that may be present therein. In addition, suitable airtemperature control devices may be arranged downstream of the heaters 57and used to control such heaters and hence the temperature of the heatedair to provide optimum drying efficiency.

The cans 23'which are to be dried are moved from a can washer, forexample, in an inverted position and placed on the horizontallyextending portion 22 of the conveyor 21 so that they may be movedthrough the drying chamber 40. Any suitable technique may be utilized toplace the cans 23 on the conveyor 22 such as by manual or automaticmeans. For example, an endless conveyor 60 may be used to move washedcans from a can washer 61, see FIG. 2, to a transfer mechanism such as ahorizontally reciprocating plate assembly 62 which transfers the cansonto the horizontal portion 22 of the conveyor 21. It will also beappreciated that the conveyor 21 may also be provided so that thehorizontally arranged portion 22 extends completely through the washerthus eliminating the need to provide a separate conveyor from the washer61 and a device to transfer the cans from the washer conveyor to theconveyor 21.

As the cans 23 are moved through the drying chamber 40 the high velocityjets of air defined by the openings 35 in the sheet 34 impingedownwardly against the bottom walls 24 of the cans 23 while sweepingpast the sidewalls 25 at a sufficiently high velocity to provideefficient transfer of heat to and hence drying of the sidewalls. As theair sweeps past the cans 23, the plate 36 with its apertures 37 helpscontrol the airflow and causes a negative pressure in a chamber 63defined beneath the plate 36 so as to provide the previously mentionedventuri effect causing circulation of the heated air within each can 23and as indicated in a somewhat exaggerated manner by the arrows 64 and65 in FIG. 6 of the drawings.

Thus, it will be seenthat the high velocity heated air bathes theoutside of each can 23 while the components of the apparatus cooperateto provide circulation of heated air within each can 23 wherebyefficient drying of both the interiors and exteriors of the cans 23 isprovided. In addition, the airflow is such that the cans 23 aremaintained in their upright positions as they pass through the dryingchamber 40.

The conveyor 21 comprising the apparatus 20 has been described as achain conveyor having a maximum open area which enables substantiallyunobstructed airflow therethrough. The conveyor 21 comprises a pluralityof links 66 each having an undulating configuration essentially as shownin FIG. 3 with each pair of adjoining links being held together by anelongated rod 67 which may extend across the full width of the conveyor21. The individual links 66 and their rods 67 may be made of anysuitable corrosion resistant material such as stainless steel or aplastic material. Yet, the construction of the conveyor 21 is such thatit may be moved in a continuous endless path.

The conveyor 21 is supported by a plurality of toothed rollers 68 whichhave cooperating teeth which are received within openings 70 definedbetween adjacent chain links 66. One of the rollers 68, shown as theupper left-hand roller in FIG. 2 and indicated at 71 is driven by asuitable drive motor to enable movement of the conveyor 21 in an endlesspath.

The plate 36 with its apertures or openings 37 is supported beneath thehorizontal portion 22 of the conveyor 21 in any suitable manner.However, in this example of the invention the plate 36 is in the form ofa support plate which is suitably fixed to the legs 44 and has a topsurface which supports the horizontal portion 22 for sliding movementthereacross with minimum frictional drag while assuring that each can 23is supported on its associated end edge 26 with optimum stability.

To minimize the frictional drag between the conveyor and the plate theconveyor 21 and/or plate 36 may have their rubbing surface portionseither made of or treated with suitable antifriction materials. Inaddition, elongated narrow strips made of an antifriction material maybe fixed on the plate 36 to reduce the rubbing area.

As previously mentioned a plurality of dampening assembly 31 is providedfor dampening any turbulence in the heated air as it approaches the cans23 and each dampening assembly is comprised of a plate 32 adjoined by ascreen 33. Each plate 32 preferably has a plurality of openings 72provided therein while each screen 33 is in the form of a large meshscreen defined by a plurality of crisscrossed undulating wires 73 which,due to the undulating character thereof, help minimize any turbulence inthe flow of heated air as it approaches the planar sheet 34 and therebyassures the provision of uniformly spaced high velocity jets of airexiting the lower surface of the plate 34 toward the cans 23, see FIG.4.

As will be apparent from FIG. 6 of the drawings, each bottom wall 24 ofeach exemplary can 23 has an outwardly concave recess or depression 74defined therein and with the cans moving into the drying apparatus 20from an associated washer in an inverted position washing fluid, such aswater, for example, is contained in each depression 74. However, thearea of each opening 35 and the spacing between openings is correlatedwith the diameter of the cans 23 to assure that at least one jet ofheated air is directed substantially normally, i.e., perpendicularly,toward the bottom wall 24 of each can 23. Thus, with the presence of awashing fluid, such as water, within a depression 74 it will be seenthat the jet of air impinging thereagainst displaces the washing fluidfrom within the depression and downwardly along the associated sidewall25 whereupon the high velocity heated air provides rapid drying of thebottom wall 24 and sidewall 25.

As previously indicated, the cooperating arrangement of the openings 35in sheet 34 and the apertures 37 in the plate 36 together with thecirculation of heated air as provided by the fan 46 results in theprovision of a positive pressure ranging roughly between one-fourth andone-half inch of water in the drying chamber 40 immediately above thesheet 34 whereby a negative pressure ranging roughly between inch and 2inches of water is provided in the chamber 63 immediately beneath plate36. This pressure distribution and the cooperating arrangement ofcomponents is such that the cans 23 are maintained in a stable uprightmanner, yet an efficient drying is provided by air flowing inside of andaround such cans.

The sheet or plate 34 is positioned a controlled distance above thebottom walls 24 of the cans 23 and as indicated at 75 in FIG. 6.Suitable means may be provided in the housing 41 to assure that thesheet 34 may be moved to accommodate cans of different heights andthereby assure impingement of air at high velocity against the bottomwalls of the cans 23 as well as high velocity flow along the sidewallsof such cans. It will also be appreciated that with the apparatus andmethod of this invention the cans 23 may be packed tightly with theirsidewalls 23 substantially in adjoining relation during movement thereofby the conveyor 21 through the drying chamber 40. With the cans tightlypacked there is less area between adjacent cans which causes highervelocity airflow along the sidewalls of the cans 23 whereby moreefficient heat transfer is provided and hence more rapid and efficientdrying of the particular cans. In particular, using the standard 12fluid oz. beverage can of circular cross-sectional configuration theeffective area between cans is roughly I0 percent of the total availablesupporting area of the horizontal portion 22 of belt 21 which is withinthe chamber 40, for example. This l0 percent area assures high velocityflow and efficient heat transfer.

The presentation of FIG. 6 has been made with the cans 23 arranged inwidely spaced relation to demonstrate the action that takes placewhereby air is circulated at high velocity around the exteriors of thecans and within the inverted cans to provide efficient high speeddrying. An efficient high speed drying action takes place which is madepossible by both convection and conduction and irrespective of whetherthe cans are widely spaced as much as or more than shown in FIG. 6 orare packed tightly together.

While a present exemplary embodiment of this invention, and method ofpracticing the same, has been illustrated and described, it will berecognized that this invention may be otherwise variously embodied andpracticed by those skilled in the art.

lclaim:

1. An apparatus for drying elongated tubular articles comprising, aconveyor for supporting said articles with their axes arrangedvertically and in parallel relation while allowing substantiallyunobstructed gas flow therethrough in a direction perpendicular to itssupporting surface, a system for circulating a drying gas around saidarticles and then toward said conveyor, means for dampening anyturbulence in said drying gas as it approaches said articles, and meansdirecting said drying gas toward said articles at high velocity and in aplurality of closely spaced jets with the spacing between jets assuringthat at least one jet is directed normally toward each of said articles.

2. An apparatus as set forth in claim 1 in which said directing meanscomprises a planar sheet having a plurality of spaced openings providedtherein defining said plurality of jets, said sheet being arrangedparallel to said conveyor and between said dampening means and saidarticles.

3. An apparatus as .set forth in claim 1 in which said dampening meanscomprises a plurality of screens arranged parallel to said conveyor.

4. An apparatus as set forth in claim 1 in which said directing meanscomprises a planar sheet having a plurality of openings therein definingsaid plurality of jets and said dampening means comprises-a screenarranged above and parallel to said planar sheet, said screen beingdefined by a plurality of crisscrossed undulating wires which helpminimize any turbulence in the flow of said drying gas as it approachessaid planar sheet. v

5. An apparatus as set forth in claim 4 and further comprising a flow.control device arranged beneath said conveyor and defining spacedapertures beneath said articles, said control device and directing meansassuring that each of said articles is maintained in an upright mannerwith said drying gas being circulated past each article at high velocityto thereby provide efficient transfer of heat to each article and dryingthereof.

6. An apparatus as set forth in claim I in which each of said articleshas a sidewall provided with opposed end edges and a wall arrangedintermediate said end edges, and further comprising a flow controldevice arranged beneath said conveyor and defining spaced aperturesbeneath said articles, said control device and directing means assuringthat each of said articles is maintained in an upright manner with saiddrying gas being circulated past each sidewall at high velocity tothereby provide'efficient transfer of heat to said sidewall andsimultaneously provide a negative pressure beneath each article andcirculationof said drying gas within each article beneath its transversewall to enable rapid drying of both the interior and exterior of eacharticle.

7. An apparatus as set forth in claim 6 in which said flow controldevice comprises a stationary planar support supporting said conveyorfor movement thereon, said support having said spaced apertures providedtherein.

8. An apparatus for drying tubular containers each having a bottom walland an adjoining sidewall terminating in an end edge defining an openend, said apparatus comprising, a

conveyor for supportingeach container in an inverted manner with its endedge resting on said conveyor, said conveyor allowing substantiallyunobstructed gas flow therethrough in a direction perpendicular to itssupporting surface, a system for circulating a drying gas against thebottom wall of each container and around its sidewall and then towardsaid conveyor, means directing said drying gas toward said is directednormally toward each of said containers, and a flow control devicearranged beneath a horizontal portion of said conveyor and definingspaced apertures beneath said containers, said flow control device anddirecting means assuring that each of said containers is maintained inan upright manner, said drying gas being circulated past each sidewallat high velocity to thereby provide efficient transfer of heat to eachsidewall and simultaneously provide a negative pressure beneath eachcontainer and circulation of said drying gas within each container toenable rapid drying of both the interior and exterior of each container.

9. An apparatus as set forth in claim 8 in which said circulating systemcomprises a system for circulating heated air with said circulatingsystem, directing means, and flow control device cooperating to providea venturi effect which causes saidnegative pressure and said circulationof heated air within each container.

10. An apparatus as set forth in claim 9 and further comprising meansfor dampening any turbulence in said drying gas, said dampening meansbeing arranged upstream of said directing means.

ll; An apparatus as set forth in claim 10 in which said negativepressure ranges between roughly a inch to 2 inches of water whichassures each of said containers is held in a stable upright manner whileproviding efiicient drying of the interior thereof. a

12. An apparatus as set forth in claim 10 in which said flow controldevice comprises a stationary planar member supported beneath saidhorizontal portion of said conveyor, said support having said spacedapertures provided therein.

13. An apparatus as set forth in claim 10 in which said directing meanscomprises a planar sheet arranged parallel to said conveyor and having aplurality of spaced openings provided therein defining said plurality ofjets.

14. An apparatus as set forth in claim 13 in which said dampening meanscomprises a plurality of sets of screen and plate assemblies arrangedparallel to said horizontal portion of said conveyor, each of said setsbeing defined by a perforated plate and an adjoining screen arrangedupstream thereof.

15. An apparatus as set forth in claim 14 in which each of said screensis defined by a plurality of crisscrossed undulating wires which alsohelp minimize any turbulence in the flow of said heated air.

16. An apparatus asset forth in claim 9 in which said conveyor comprisesan endless chain link conveyor and said circulating system comprises aclosed loop system which reheats and recirculates the air past thecontainers being dried by said apparatus.

l7. An apparatus as set forth in claim 9 in which each bottom wall ofeach container has an outwardly concave depression defined therein andwith said containers moving from a washer to said apparatus in aninverted manner washing fluid vis contained in said depression, and withsaid directing means assuring that at least one jet of air is directedjets with the spacing between jets assuring that at least one jetnormally toward each container the washing fluid is displaced fromwithin its depression by the action of an associated jet of air whilethe associated container is maintained in an upright position.

1. An apparatus for drying elongated tubular articles comprising, aconveyor for supporting said articles with their axes arrangedvertically and in parallel relation while allowing substantiallyunobstructed gas flow therethrough in a direction perpendicular to itssupporting surface, a system for circulating a drying gas around saidarticles and then toward said conveyor, means for dampening anyturbulence in said drying gas as it approaches said articles, and meansdirecting said drying gas toward said articles at high velocity and in aplurality of closely spaced jets with the spacing between jets assuringthat at least one jet is directed normally toward each of said articles.2. An apparatus as set forth in claim 1 in which said directing meanscomprises a planar sheet having a plurality of spaced openings providedtherein defining said plurality of jets, said sheet being arrangedparallel to said conveyor and between said dampening means and saidarticles.
 3. An apparatus as set forth in claim 1 in which saiddampening means comprises a plurality of screens arranged parallel tosaid conveyor.
 4. An apparatus as set forth in claim 1 in which saiddirecting means comprises a planar sheet having a plurality of openingstherein defining said plurality of jets and said dampening meanscomprises a screen arranged above and parallel to said planar sheet,said screen being defined by a plurality of crisscrossed undulatingwires which help minimize any turbulence in the flow of said drying gasas it approaches said planar sheet.
 5. An apparatus as set forth inclaim 4 and further comprising a flow control device arranged beneathsaid conveyor and defining spaced apertures beneath said articles, saidcontrol device and directing means assuring that each of said articlesis maintained in an upright manner with said drying gas being circulatedpast each article at high velocity to thereby provide efficient transferof heat to each article and drying thereof.
 6. An apparatus as set forthin claim 1 in which each of said articles has a sidewall provided withopposed end edges and a wall arranged intermediate said end edges, andfurther comprising a flow control device arranged beneath said conveyorand defining spaced apertures beneath said articles, said control deviceand directing means assuring that each of said articles is maintained inan upright manner with said drying gas being circulated past eachsidewall at high velocity to thereby provide efficient transfer of heatto said sidewall and simultaneously provide a negative pressure beneatheach article and circulation of said drying gas within each articlebeneath its transverse wall to enable rapid drying of both the interiorand exterior of each article.
 7. An apparatus as set forth in claim 6 inwhich said flow control device comprises a stationary planar supportsupporting said conveyor for movement thereon, said support having saidspaced apertures provided therein.
 8. An apparatus for drying tubularcontainers each having a bottom wall and an adjoining sidewallterminating in an end edge defining an open end, said apparatuscomprising, a conveyor for supporting each container in an invertedmanner with its end edge resting on said conveyor, said conveyorallowing substantially unobstructed gas flow therethrough in a directionperpendicular to its supporting surface, a system for circulating adrying gas against the bottom wall of each container and around itssidewall and then toward said conveyor, means directing said drying gastoward said contaIners at high velocity and in a plurality of closelyspaced jets with the spacing between jets assuring that at least one jetis directed normally toward each of said containers, and a flow controldevice arranged beneath a horizontal portion of said conveyor anddefining spaced apertures beneath said containers, said flow controldevice and directing means assuring that each of said containers ismaintained in an upright manner, said drying gas being circulated pasteach sidewall at high velocity to thereby provide efficient transfer ofheat to each sidewall and simultaneously provide a negative pressurebeneath each container and circulation of said drying gas within eachcontainer to enable rapid drying of both the interior and exterior ofeach container.
 9. An apparatus as set forth in claim 8 in which saidcirculating system comprises a system for circulating heated air withsaid circulating system, directing means, and flow control devicecooperating to provide a venturi effect which causes said negativepressure and said circulation of heated air within each container. 10.An apparatus as set forth in claim 9 and further comprising means fordampening any turbulence in said drying gas, said dampening means beingarranged upstream of said directing means.
 11. An apparatus as set forthin claim 10 in which said negative pressure ranges between roughly 1/2inch to 2 inches of water which assures each of said containers is heldin a stable upright manner while providing efficient drying of theinterior thereof.
 12. An apparatus as set forth in claim 10 in whichsaid flow control device comprises a stationary planar member supportedbeneath said horizontal portion of said conveyor, said support havingsaid spaced apertures provided therein.
 13. An apparatus as set forth inclaim 10 in which said directing means comprises a planar sheet arrangedparallel to said conveyor and having a plurality of spaced openingsprovided therein defining said plurality of jets.
 14. An apparatus asset forth in claim 13 in which said dampening means comprises aplurality of sets of screen and plate assemblies arranged parallel tosaid horizontal portion of said conveyor, each of said sets beingdefined by a perforated plate and an adjoining screen arranged upstreamthereof.
 15. An apparatus as set forth in claim 14 in which each of saidscreens is defined by a plurality of crisscrossed undulating wires whichalso help minimize any turbulence in the flow of said heated air.
 16. Anapparatus as set forth in claim 9 in which said conveyor comprises anendless chain link conveyor and said circulating system comprises aclosed loop system which reheats and recirculates the air past thecontainers being dried by said apparatus.
 17. An apparatus as set forthin claim 9 in which each bottom wall of each container has an outwardlyconcave depression defined therein and with said containers moving froma washer to said apparatus in an inverted manner washing fluid iscontained in said depression, and with said directing means assuringthat at least one jet of air is directed normally toward each containerthe washing fluid is displaced from within its depression by the actionof an associated jet of air while the associated container is maintainedin an upright position.